Obesity Flashcards
What is the primary factor in the development of obesity?
Genotype
decreased activity, ease of increased caloric intake, socialization, age, sex, race and economic status are what factors in the development of obesity?
Environment
T/F: Adipose tissue is considered an organ
True
____ Leading Cause of preventable death
(10% - 50% greater chance of death from all causes)
Affects ___ of adults in America
35% have BMI > 30
2nd
3/4
More stats on slide 3
Calculation for BMI
Weight(kg)/height(m2)
(Weight[lbs}/Height[in2]) X 703
What are the BMI classes
25-29.9 Overweight 30-34.9 Obese Class I 35-39.9 Obese Class II 40-44.9 Obese Class III/Morbidly Extreme Obese >45 Obese Class IV/Severe Obesity
Calculation for ideal body weight (IBW)
Broca’s Index
Male = Height(cm) – 100 Female = Height(cm) – 105
Calculation for lean body weight
IBW x 1.3
Lean body weight is 30% higher than IBW, why?
due to extra muscle mass developed to carry extra weight
Adipose Tissue: Major physiologic function
Secretes
protein
Adipose Tissue: Major physiologic function
Endocrine organ -
readily convertible and usable energy
heat insulation
Adipose Tissue: Major physiologic function
Liver fat metabolism - why is this important?
because all cells contain some unsaturated fats synthesized by the liver
Degradation of fatty acids into usable units of energy
Synthesis of triglycerides from carbohydrates and proteins
Synthesis of other lipids from fatty acids (particularly cholesterol and phospholipids)
What is android distribution?
Central or abdominal visceral
Apple shaped
In the android distribution, waist/hip ratio is greater than ___ in men and ____ in women.
0.85 men
0.92 women
Correlated with higher risk of comorbidities
What is gynecoid distribution?
Gluteal femoral or peripheral
Pear shaped
Which type of obesity is associated with greater amount of comorbidities?
Android
heart disease, DM, HTN, dyslipidemia, death
What is gynecoid obesity associated with?
Varicose veins, joint disease
Cardiac pathophysiology:
Increased metabolic demand from..
Increased Cardiac Output of ___ for each kg of fat
fat organ
0.1 L/mi
Cardiac pathophysiology:
Increased ____ and increased ____
For every ____ of fat = 25 miles of neovascularization
Increase ____ + _____ = HTN
Vessels and volume
13.5 kg
Increase volume + RAA activation = HTN
Cardiac pathophysiology:
Increased workload to meet demand has what effects
Increased CO, O2 consumption, CO2 production
Cardiomegaly, atrial and biventricular dilatation and hypertrophy
Is CAD a dependent or indépendant factor with obesity?
independent
Definition of HTN in obesity
SBP > 140, DBP > 90, or both
2 times risk in obesity
Why is there a 2X risk of HTN in obesity?
Increased blood viscosity Hyperinsulinemia Increased mineralocorticoids Sodium reabsorption Compression of kidneys Impaired sodium excretion RAA activation
Respiratory pathophysiology
Why is there decreased compliance?
Pressure from abdominal, diaphragmatic , and thoracic fat
What is the F/V loop pattern?
Restrictive
Inhibited lung inflation leads to
Decreased:
Increased:
No change:
Decreased: FRC, ERV, VC, TLC
Increased: dead space
No change: RV, CC, FVC, FEV1
Why is there a decreased FRC to < closing capacity?
Increased dead space, vq mismatch, shunting, hypoxemia
What else does obesity lead to with respiratory?
Hypoventilation, hypercarbia, acidosis
OSA rates are ____ portion to BMI
directly
Risk factors for OSA in obesity
BMI > 30
abdominal fat distribution
large neck girth
Definition of OSA
Excessive episodes of apnea (10 seconds) and hypopnea
Estimated that 80%-95% are undiagnosed
How do episodes of apnea work in OSA
Obstruction –> hypoxia and hypercarbia –> surge of muscles to open airway –> period of hyperventilation –> reverses hypercarbia –> normal breathing –> start all over
In OSA, > 5 episodes per hour or 30 per night
this will lead to what?
Hypoxia, hypercapnia, systemic and pulmonary hypertension, and cardiac arrythmias
In pre-op, what questions should you ask about sleep apnea?
ask about sleeping patterns, snoring or apnea, arousals, diurnal sleepiness
What is the gold standard test for OSA
polysomnography (PSG)
STOP-BANG
Snoring Tiredness Observed apnea High BP BMI (greater than 35) Age (greater than 50) Neck circumference (>40cm/15.75in) Gender (male)
Surgery centers should not do patients with a BMI >
45
What is obese hypoventilation (pickwickian syndrome)?
Inappropriate and sudden somnolence, OSA, Hypoxia, Hypercapnia, arterial hypoxemia, cyanosis-induced polycythemia, respiratory acidosis, pulmonary hypertension, Right sided heart failure
How does pickwickian lead to right sided heart failure
HPV –> pulmonary HTN –> cor pulmonale
GI risks with obesity
GERD, gallstones, pancreatitis
Fatty liver disease – 3% develop cirrhosis
NAFLD (non-alcoholic fatty liver disease)
DM risk with obesity
80% of NIDDM pts are obese
Risk linear to BMI
Metabolic syndrome with obesity
Glucose intolerance, DM2, HTN, dyslipidemia, CVD
Cardiovascular risk 50%-60% above normal
Ortho risk with obesity
Osteoarthritis from mechanical stress
How much of pediatric population is considered obese?
16.9% age 2-19 considered obese
Weight for height ratio > 90%
BMI > 95%
Complications with obesity and pregnancy correlate more with _____
pre-pregnancy obesity
Gestational DM, preeclampsia, preterm labor, c-section, postpartum hemorrhage, infection, PIH (pregnancy-induced hypertension), macrosomic infants
Double 1st 6 weeks miscarriage
Is the complication risk in pregnancy increased or decreased after bariatric surgery?
increased
What are the altered body compositions for pharmacology in obese patients?
Increased Vd
Increased blood volume
Decreased total body water
Alterations of protein binding & lipophilicity of drug
Ideal Body Weight vs. Total Body Weight
Meds low lipophilicity =
Meds high lipophilicity =
inhaled anesthetic
IBW
TBW most of the time (digoxin, remifentanil, procainamide)
sevo and des
Pharmacokinetic changes with obesity
Increased:
Decreased:
Increased: fat mass, C.O., blood volume, lean body weight, renal clearance, volume of distribution of lipid soluble drugs
Decreased:total body water, pulmonary function
Changes in plasma binding, abnormal liver function
(Pg 1007)
GA induction - \_\_\_% reduction in FRC \_\_\_\_ achieves improvement in FRC and arterial O2 tension, may decrease CO and O2 delivery \_\_\_\_ ml/kg IBW for volumes Intermittent manual \_\_\_\_ may help FRC
50%
PEEP
6-10
“sighs”
In obese patients, there is an increased ____ BUT proportionately decreased _____
total body volume
Estimated blood volume
What EBV is used for obese patients
45-55 ml/kg
